References Christian, R. (1990) Butterley brick: 200 years in the making, London: Henry Melland, Cooper, B. (1991) Transformation of a valley: the Derbyshire Derwent, Cromford: Scarthin, Lowe, J.W. (1975) British steam locomotive builders, Cambridge: Goose, , republished 1989 by Guild Riden, P. (1990) The Butterley Company 1790–1830, Derbyshire Records Society, Schofield, R.B. (2000) Benjamin Outram 1764–1805 : an engineering biography, Cardiff: Merton Priory, Footnotes Duke of Portland's estate papers relating to Coal seams (Derbyshire & Notts) External links Archive of the Butterley Engineering web site (now defunct) archived at the Internet Archive as of April 2012 D503 - Papers of the Butterley Company (the document collection from the Butterley Company is held by the Derbyshire Record Office). Butterley Ironworks Iron Smelt Mill at AditNow "the definitive online resource for the mine explorer and mining historian" Engineering companies of the United Kingdom Companies based in Derbyshire